Nitrogen and sulfur oxides
Pollutants in car exhaust can be divided into those that inflict global damage and those that cause local pollution. The former includes carbon dioxide and other substances contributing to global warming, while nitrogen and sulfur oxides cause direct local health damage. A high concentration of nitrogen oxides in the air along high-traffic motorways can trigger asthma and other conditions. To reduce these pollutants, the government has defined basic guidelines, and is implementing a reduction program and regulating the types of vehicles allowed. The automobile industry is developing low-pollution vehicles with the exhaust from which contains a lower volume of pollutants.
Development of low-pollution vehicles
Concern is growing regarding localized air pollution caused by car exhaust as well as global warming attributed to carbon dioxide emissions. One countermeasure for these problems is the development and promotion of low-pollution cars. The idea is to reduce the burden on the environment by improving performance. Technologically viable low-pollution vehicles include methanol cars, hybrid cars, compressed natural gas cars, and electric cars. At this point, all of these are more expensive than conventional cars. Therefore, the introduction of such vehicles has so far been limited to some bus operators and government offices. However, the release of hybrid cars is slowly expanding public use of low-pollution cars. The government has also implemented measures to promote such vehicles, including tax incentives.